Our peer-reviewed sister journal: Lignocellulose (no author payment)
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BioResources, Volume 3, Issue 3
NOTE: Each current issue of BioResources continues to build as new articles are approved.
Traditional chemical industry depends on non-renewable fossil resources and is now facing great challenges. Lignocellulosic materials are the most abundant renewable resources in the world, and their efficient utilization provides a practical route to maintain sustainable development of chemical industry. Modern chemical technology as well as industrial biotechnology will play an important role in comprehensive utilization of lignocellulosic materials in an environmentally friendly way. Bio-refinery is a useful concept in use when considering lignocellulosic materials for a sustainable chemical industry. PDF
Recently an excellent book on lignocellulosic-based biomass has been published. The book can be expected to profoundly impact research and development for sustainable science and engineering. For this reason we have decided to provide our readers with a review of this new ACS Press book entitled “Materials, Chemicals & Energy from Forest Biomass” edited by Dimitris S. Argyropoulos from NC State University. The book features unique, peer-reviewed chapters that were submitted to the American Chemical Society’s Pacifi-Chem 2005 Meeting in Honolulu, Hawaii. It presents a timely and focused review of research efforts encompassing work from the most pertinent derivatives of wood and related resources that include new polymers, composites, niche chemicals, and biofuels. This book will ultimately serve a number of disciplines and promises to focus the discussion of biomass for new avenues of chemicals, fuels, and materials. PDFMartín, C., Marcet, M., and Thomsen, A. B. (2008). "Comparison between wet oxidation and steam explosion as pretreatment methods for enyzmatic hydrolysis of sugarcane bagasse," BioRes. 3(3), 670-683.
Alkaline wet oxidation and steam explosion pretreatments of sugarcane bagasse were compared with regard to biomass fractionation, formation of by-products, and enzymatic convertibility of the pretreated material. Wet oxidation led to the solubilisation of 82% of xylan and 50% of lignin, and to a two-fold increase of cellulose content in the pretreated solids, while steam explosion solubilised only 60% of xylan and 35% of lignin and increased cellulose content in the solid material by one third. Wet oxidation formed more aliphatic acids and phenolics, and less furan aldehydes in the liquid fraction than steam explosion did. A better enzymatic convertibility of cellulose was achieved for the wet-oxidised material (57.4 %) than for the steam-exploded material (48.9 %). Cellulose convertibility was lower for the whole slurry than for the washed solids in both pretreatments, but more significantly in steam explosion. This investigation demonstrates the potential of wet oxidation as a promising pretreatment method for enzyme-based bagasse-to-ethanol processes. PDFPorankiewicz, B., and Wieloch, G. (2008). "Sanding of Fagus silvatica L. wood perpendicularly to the grains," BioRes. 3(3), 684-700.
In this paper the dependencies of the degree of surface burning and intensity during disc sanding perpendicular to the wood grains of Fagus silvatica L. were examinedfor several machining parameters. Significant impacts of sanding load, thickness, and width of a wooden specimen on the surface burning and disc sanding intensity were evidenced and analyzed by evaluation of multi-factor, non-linear relations. Less important influences of cutting speed and size of grit on the surface burning and the sanding intensity, as well as single sanding cycle time and total sanding operating time on the surface burning were observed. PDF
Lima, C. F., Barbosa, L. C. A., Marcelo, C. R., Silvério, F. O., and Colodette, J. L. (2008). "Comparison between analytical pyrolysis and nitrobenzene oxidation for determination of syringyl/guaiacyl ratio in Eucalyptus spp. lignin," BioRes. 3(3), 701-712.
Pyrolysis-gas chromatography/mass spectrometry (Py-GC-MS) was applied to measure the lignin syringyl/guaiacyl (S/G) ratio in E. dunni, E. grandis, E. nitens, E. urograndis, and E. urophylla woods. A total of 41 compounds were identified, of which 11 were derived from carbohydrates and 30 from lignins. The S/G ratio was calculated on the basis of the areas of peaks recorded in the pyrograms and compared with the results obtained by alkaline nitrobenzene oxidation. The values of S/G found by pyrolysis were similar for all the species using the compounds guaiacol, 4-methylguaiacol, 4-vinylguaiacol, vanillin, 4-ethylsyringol, 4-vinylsyringol, homosyringaldehyde, acetosyringone, and syringylacetone, as lignin markers. The selected markers were efficient for the deter-mination of S/G ratio in eucalyptus wood by Py-GC-MS. The Py-GC-MS technique produced results that are comparable to the nitrobenzene oxidation method, with the advantage of requiring small wood samples and a short analysis time. PDF
Spruce galactoglucomannan is a wood-derived polysaccharide with a modest molar mass that has recently been made available in kg-scale for research and development of value-added products. To promote the application of spruce galactoglucomannans in, for example, food products, it is vital to understand also the rheological behaviour of the mixtures of galactoglucomannans with other polysaccharides. Rheological measurements were applied to study the rheological properties of mixtures of spruce galactoglucomannans and high-molar-mass konjac glucomannan, xanthan, guar gum, locust bean gum, and carrageenan. Shear rate-dependence of viscosity and applicability of the Cox-Merz relationship of mixtures of spruce galactoglucomannans with the other polysaccharides were studied. Spray-dried and ethanol-precipitated galactoglucomannans were also prepared for comparison. The effects of polysaccharide mixture ratio, temperature, ionic strength, and deacetyl-ation are discussed. Mixtures of spray-dried galactoglucomannans and konjac glucomannan showed lower elastic properties than those of ethanol precipitated galactoglucomannans and konjac glucomannan. The viscoelastic spectra of mixtures of both galactoglucomannans and deacetylated galactoglucomannans with konjac glucomannan showed temperature dependency throughout the cooling process. Ionic strength had an effect on the rheological properties of mixtures of galactogluco-mannans with konjac glucomannan. Deacetylation of galactoglucoman-nans did not affect the viscoelastic spectra significantly. PDFPatyakin, V. I., Sugaipov, U. U., Birman, A. R., Bazarov, S. M., Pilshikov, Y. N., Spitsyn, A. A., and Mettee, H. D. (2008). "Mechanical and chemical modification of wood materials - Compressed wood and oxidized charcoal," BioRes. 3(3), 731-744.
Mechanical compression and electrolyte infusion of wood, pyrolysis, and chemical activation of the resulting charcoals produced enhanced abilities to adsorb lead ion and benzene from model polluted water solutions. Iodine number (F) and methylene blue (E) indices also showed enhancement of surface activity. Ultrasonic techniques revealed a loss of pore structure during wood compression, as water infiltration likewise indicated for the resulting charcoals, but there was not necessarily a loss of adsorption ability for the above adsorbents on subsequent charcoals. Aspen based charcoals activated by pressurized H2O2 showed the most promise among those tested. PDF
In this paper a dependence of the main cutting force upon several machining parameters by wood of black locust (Robinia pseudoaccacia L.) during straight turning was graphically illustrated and analyzed. Evidence for several interactions was found based on multi-factor nonlinear equations evaluated from an experimental matrix. PDF
Imam, S. H., Chiou, B.-S., Woods, D., Shey, J., Glenn, G. M., Orts, W. J., Narayan, R., Avena-Bustillos, R. J., McHugh, T. H., Pantoja, A., and Bechtel, P. J. (2008). "Starch/pulp-fiber based packaging foams and cast films containing Alaskan fish by-products (waste)," BioRes. 3(3), 758-773.
Baked starch/pulp foams were prepared from formulations containing zero to 25 weight percent of processed Alaskan fish by-products that consisted mostly of salmon heads, pollock heads, and pollock frames (bones and associated remains produced in the filleting operation). Fish by-products thermoformed well along with starch and pulp fiber, and the foam product (panels) exhibited useful mechanical properties. Foams with all three fish by-products, ranging between 10 and 15 wt%, showed the highest flexural modulus (500-770 Mpa). Above 20% fiber content, the modulus dropped considerably in all foam samples. Foam panels with pollock frames had the highest flexural modulus, at about 15% fiber content (770 Mpa). Foams with salmon heads registered the lowest modulus, at 25% concentration. Attempts were also made to cast starch-glycerol-poly (vinyl alcohol) films containing 25% fish by-product (salmon heads). These films showed a tensile strength of 15 Mpa and elongation at break of 78.2%. All foams containing fish by-product degraded well in compost at ambient temperature (24oC), loosing roughly between 75-80% of their weight within 7 weeks. The films degraded at a much higher rate initially. When left in water, foams prepared without fish by-product absorbed water much more quickly and deteriorated faster, whereas, water absorption in foams with fish by-product was initially delayed and/or slowed for about 24 h. After this period, water absorption was rapid. PDF
Ni, W., Xu, Q., Jiao, J.-X., Liu, X., and Ren, C. (2008). "Hierarchically porous Fe2O3 and Fe2O3/SiO2 composites prepared by cypress tissue template with assistance of supercritical CO2," BioRes. 3(3), 774-788.
Hierarchically porous α-Fe2O3 and silica-based Fe2O3 composites (I & II) ranging from nanopores to micrometer-sized pores have been prepared by a nanoscale casting process, using cypress wood tissue template in supercritical carbon dioxide (scCO2). These wood-templated Fe2O3 and its SiO2-based composites with special hierarchical but continuous pore size from 9 nm up to 20 μm, were prepared from scCO2’ hybrid solution with cosolvent and precursor(s). Different characterization techniques such as SEM, XRD, and N2 adsorption-desorption were used to investtig-ate the morphology and structure of Fe2O3 and its composites in different length scales. The Fe2O3 porous material showed a specific character-istic of being accumulated by Fe2O3 granules in the size range ca. 100–200 nm. The SiO2-based Fe2O3 composites exhibited a BET area of 99–104 m2/g, which was much higher than that of pure Fe2O3; this implies that the silica probably exists in the form of a gel skeleton. PDF
Beech sawdust was reacted with phthalic (PA) and maleic (MA) anhydrides for chemical modification. The influence of reaction time and anhydride amount was investigated. IR spectra gave evidence of wood esterification. Thermogravimetric investigation of chemically modified wood indicated a better thermal stability (mainly for wood treated with phthalic anhydride) in comparison with the untreated wood. PDFLei, X., Lin, L., and Li, K. (2008). "Effect of xylanase pretreatment of wood chips on fiber separation in the CTMP refining process," BioRes. 3(3), 801-815.
The effect of xylanase treatment of eucalyptus wood chips on chip refining and fiber properties was investigated. The fiber separation region and fiber surface structure were observed with SEM, TEM, and AFM. The fiber length and fines were analyzed with a Bauer-McNett classifier and optical image analysis of flowing suspensions (FQA). The results showed that xylanase degraded and hydrolyzed some xylan in the fiber wall, thus loosening the fiber wall structure. Therefore, in the subsequent refining process, fiber separation occurred in the secondary wall. This resulted in fibers with less lignin and extractives on the surface, which will benefit the interfiber bonding. PDF
Jahan, M. S., Ahsan, L., Noori, A., and Quaiyyum, M. A. (2008). "Process for the production of dissolving pulp from Trema orientalis (nalita) by prehydrolysis kraft and soda-ethylenediamine (EDA) process,"BioRes. 3(3), 816-828.
This paper presents a preliminary study for the production of dissolving pulp from Trema orientalis (Nalita). Water prehydrolysis kraft and soda-ethylenediamine (EDA) pulping for the production of dissolving pulp from T. orientalis was investigated. Prehydrolysis at 150 and 170 oC did not produce pulp with high α-cellulose content when using the kraft process. But addition of 0.25 % H2SO4 in prehydrolysis liquor increased the purity of the pulp with the sacrifice of pulp yield and viscosity. The soda-EDA process produced better pulp yield, kappa number, viscosity, and α-cellulose content as compared to the kraft process. Increasing EDA charge in the soda liquor increased pulping selectivity and α-cellulose content. Degraded cellulose (R18-R10) in soda-EDA pulp was lower than kraft pulp. But the bleachability of soda-EDA pulp was inferior as compared to kraft pulp in DED bleaching. PDFKeheyan, Y. (2008). "PY/GC/MS analyses of historical papers," BioRes. 3(3), 829-837.
The thermal degradation of cellulose is an important process in several fields such as the paper industry, biomass combustion, fire retardation, etc. Paper consists mostly of cellulose fibres. Although the fibre source has changed continiously from cotton or linen rags to wood, its nature is still vegetal. Pyrolysis in combination with gas chromatography and mass spectrometry has been used to identify the structures of thermal degradation products with the aim to characterize papers used in different centuries. Pyrolysis of cellulose has also been studied in the presence of the methylating reagent tetramethylammonium hydroxide (TMAH). PDFPorankiewicz, B., Iskra, P., Jóźwiak, K., Tanaka, C., and Zborowski, W. (2008). "High speed steel tool wear after wood milling in the presence of high temperature tribochemical reactions," BioRes. 3(3), 838-858.
Wear patterns were analyzed for High Speed Steel (HSS) SKH51 cutting tools after milling wood of four wood species having very different High Temperature Tribochemical Reactions (HTTR), wood density and very low hard mineral contamination (HMC). The experimental results showed that the HTTR can be an important factor influencing acceleration of cutting tool wear. PDF
A new type of binder for wood particles or fibres was developed using a recycled polyol from polyurethane or PET wastes and a polyisocyanate as raw materials. The binders developed with various ratios of hydroxyl and isocyanate groups are solid at room temperature with melting points between 40 and 60°C. Between 5 and 20% of these were mixed with the wood products and compression-moulded at temperatures between 80 and 100°C and 0.75 to 2.05 kp/mm² pressure to give composites of tensile strength up to 47 N/mm2 or flexural strength up to 58 N/mm2. PDFHan, Y., Law, K.-N., and Lanouette, R. (2008). "Modification of jack pine TMP long fibers by alkaline peroxide - Part 1. Chemical characteristics of fibers and spent liquor," BioRes. 3(3), 870-880.
The purpose of this work was to improve the quality of jack pine TMP long fibers, particularly with respect to the strength properties, by alkaline peroxide treatment. This paper reports the chemical characteristics of the treated long fibers and the spent liquors originating from various treatments. It was observed that, in comparison with hydrogen peroxide, the alkalinity of the treatment solutions had a greater influence on most fibre characteristics and spent liquor properties. PDFRabelo, M. S., Colodette, J. L., Sacon, V. M., Silva, M. R., and Azevedo, M. A. B. (2008). "Molybdenum catalyzed acid peroxide bleaching of eucalyptus kraft pulp," BioRes. 3(3), 881-897.
Molybdenum catalyzed peroxide bleaching (PMo Stage) consists of pulp treatment with hydrogen peroxide under acidic conditions in the presence of a molybdenum catalyst. Molybdenum is applied in catalytic doses (50-200 mg/kg pulp) and may originate from various sources, including (NH4)6Mo7O24.4H2O, Na2MoO4.2H2O, siliconmolybdate, etc. This work is aimed at optimizing the PMo stage and evaluating its industrial application in the OAZDP sequence. Optimum PMo stage conditions for bleaching eucalyptus pulp were 90 ºC, pH 3.5, 2 h, 0.1 kg/adt Mo and 5 kg/adt H2O2. The PMo stage was more efficient to remove pulp hexenuronic acids than lignin. Its efficiency decreased with increasing pH in the range of 1.5-5.5, while it increased with increasing temperature and peroxide and molybdenum doses. The application of the PMo stage as replacement for the A-stage of the AZDP sequence significantly decreased chlorine dioxide demand. The PMo stage caused a decrease of 20-30% in the generation of organically bound chlorine. The quality parameters of the pulp produced during the PMo stage mill trial were comparable to those obtained with the reference A-stage. PDF
The thermostable enzyme systems produced by the thermophilic ascomycete fungus Talaromyces emersonii cultivated on various carbon sources were investigated for the production of high value products from sugar beet. A broad range of enzymatic activities relevant to cellulose, hemicellulose, and pectin hydrolysis were identified in T. emersonii culture filtrates. In hydrolysis experiments conducted at 71ºC, the enzyme cocktails generated sugar-rich syrups from untreated sugar beet plants. Maximal levels of sugar beet hydrolysis were obtained with T. emersonii enzyme cocktails induced with sorghum/ beet pulp (68%) and sugar beet plant (56%). The principle monosaccharides released were glucose, xylose, and arabinose with minor amounts of galactose and galacturonic acid. Northern analysis of RNA isolated from T. emersonii when sugar beet plants were used as the sole carbon inducing source showed that genes required for polysaccharide hydrolysis and five carbon monosaccharide metabolism were co-ordinately expressed. PDF
Esteban, L. S., Ciria, P., and Carrasco, J. E. (2008). "An assessment of relevant methodological elements and criteria for surveying sustainable agricultural and forestry biomass byproducts for energy purposes," BioRes. 3(3), 910-928.
Resource assessment is a necessary step for any project, plan, or future energy prospectus involving renewable energy sources. The assessment of biomass and, in particular, the so-called forest and agricultural field residues, faces particular methodological difficulties due to the scarcity and heterogeneity of the data sources. For agricultural residues such as cereal straw, bagasses, etc., the residue to product ratios (RPR) are the key data needed for the estimations. In the present work the values of these product ratios reported in the literature are surveyed and are seen to vary greatly, depending on the reporting source. Some methodological procedures for obtaining RPR values are considered, and guidelines for conducting the resource evaluation are indicated. For the estimation of forest field biomass resources a methodological procedure based on the different stand stages along a forest rotation is presented. The main steps of this methodology are based on the availability of basic quantitative data from forest stands and the assumption of different silvicultural operations during the stand rotations. Environmental constraints should be observed in biomass resource assessments. However, the lack of clear recommendations concerning biomass removal in different forest soil and climate conditions suggest that more research is required to assess the sustainability of biomass harvest. Chemical characterization of some of the most representative biomass materials is also presented. PDF
Because of their wide abundance, their renewable and environmentally benign nature, and their outstanding mechanical properties, a great deal of attention has been paid recently to cellulosic nanofibrillar structures as components in nanocomposites. A first major challenge has been to find efficient ways to liberate cellulosic fibrils from different source materials, including wood, agricultural residues, or bacterial cellulose. A second major challenge has involved the lack of compatibility of cellulosic surfaces with a variety of plastic materials. The water-swellable nature of cellulose, especially in its non-crystalline regions, also can be a concern in various composite materials. This review of recent work shows that considerable progress has been achieved in addressing these issues and that there is potential to use cellulosic nano-components in a wide range of high-tech applications. PDF